I remember this from school:
1. Obtain 15 lb. of ripe yellow bananas.
2. Peel the bananas and eat the fruit. Save the skins.
3. With a sharp knife, scrape off the insides of the skins and save the scraped material.
4. Put all scraped material in a large pot and add water. Boil for three to four hours until it has attained a solid paste consistency.
5. Spread this paste on cookie sheets and dry it in an oven for about 20-30 minutes. This will result in a fine black powder (bananadine). Usually one will feel the effects of bananadine after smoking three or four cigarettes.
It's a hoax!
Bananadine is a fictional psychoactive substance which is allegedly extracted from banana peels. A recipe for its extraction from banana peel was originally published as a hoax in the Berkeley Barb in March 1967. It became more widely known when William Powell, believing it to be true, reproduced the method in The Anarchist Cookbook in 1970 under the name "Musa Sapientum Bananadine" (referring to the banana's binomial nomenclature). The original hoax was designed to raise questions about the ethics of making psychoactive drugs illegal and prosecuting those who took them; "what if the common banana contained psychoactive properties, how would the government react?".
Researchers at New York University have found that banana peel contains no intoxicating chemicals, and that smoking it produces only a placebo effect. Over the years, bananadine has become a popular urban legend.